U.S. Pat. No. 8,828,895 describes the unique method of making filter fabrics by utilizing mono-component; mono-constituent fibers made from both high and low melt temperature Polylactic Acid (PLA) fibers. Further, Published US Application 20140242309 describes improvements by creating layers of different fiber blends and different shapes of fibers to improve filtration while enhancing performance.
Even with the significant improvements given by the above, there still exists a need in the art to increase elongation of non-woven fabrics to enhance moldability. In addition, there is a need to reduce overall costs by avoiding the process of making low melt fibers.
Furthermore, many municipal water supplies add chlorine to the drinking water supplies to reduce or kill bacteria in the water system. Chlorine may significantly change the taste of the water and leave a residual or bad taste in the beverage made from the water when it is diffused through most filter fabrics. This bad taste may affect the taste of infused or brewed beverages, such as tea, coffee, and many other beverages made with this water. Thus, there is also a need in the art to decrease the amount of chlorine in the water being diffused.
In the United States, a cup of coffee is generally produced under atmospheric pressure with hot water flowing through the coffee grounds and through a filter. The resultant coffee is coloring the water from light grey to black, but still maintains a clarity. In Europe as well as most of the rest of the world, coffee is generally produced under a pressure greater than 1 atmosphere and the coffee is generally ground to finer particles. As a result, coffee is cloudy, stronger and has a “crema” or foam on the surface. Such coffee is sipped slowly to enjoy the enhanced flavor.
In all cases, there need for a tortuous path for the water to flow through a filter that will allow a fast flow, but preventing any particles from flowing into the cup. It is believed that a tortuous path will allow more complete transfer of the coffee essence from the grounds to the liquid, while at the same time increasing the “crema”.
Cellulosic “paper” products have an inverse relationship of weight with porosity. As cellulosic papers get higher than 30 gsm in weight, at that point porosity approaches zero and become impermeable. In order to preserve breathability at higher basis weights, “paper” manufacturers will use large percentages of fibers bound together by binders. Further cellulose fibers swell on contact with water, further closing the pores of the paper.
There is also a need for an infusion substrate, particularly for tea and coffee, which provides rapid infusion of hot water into the tea or coffee particles, while being strong enough to keep the particles within a bag or pouch made up in substantial part or wholly of such substrate. There is also a need for heat-sealable pouch for tobacco and tobacco products (i.e. snuff and chewing tobacco).
Further, it is highly desirable that the substrate media be 100% biodegradable and not contain any inert or non-biodegradable components. It is also highly desirable that the media, including all of the production scrap, be recyclable into itself.